1. Field of the Invention
The invention relates to automatic carwash systems and particularly to equipment for economically and efficiently cleaning the tire side walls of vehicles passing through the carwash system. More particularly, the invention relates to a treadleplate construction which is depressed by one of the tires of a passing vehicle, which in turn opens a cleaning solution spray valve for a predetermined amount of time, which is in direct relationship to the size of the particular vehicle being cleaned to provide efficient and economic use of the cleaning solution while insuring complete cleaning of the vehicle tires.
2. Description of the Prior Art
In recent years automatic carwash establishments have gained significant popularity in all areas of the country. Most of these automatic carwash systems use means, such as a chain driven conveyor, to pull a vehicle at a predetermined rate of speed through a series of washing, rinsing and drying operations or stations spaced along the conveyor path. Many of these systems operate on a predetermined, programmed timing cycle which is dependent upon the speed of the moving conveyor or vehicle to perform the various cleaning operations on the vehicle as it reaches a particular cleaning station. Other types of automatic carwash systems have contact switches placed along the vehicle travel path which are depressed by the passing vehicle to actuate the particular cleaning equipment at that station. After passage of the vehicle, the initial switch is released or a second switch is depressed to deactivate the previously actuated station equipment.
At one of the stations a cleaning solution is sprayed directly against the side walls of the vehicle tires by a plurality of spray nozzles as the vehicle moves along the conveyor for cleaning the tires. The spray nozzles usually are mounted directly on the floor of the carwash or on supports located adjacent the side of the path of the vehicle tires. These nozzles are actuated for a predetermined amount of time which is sufficient to insure complete coverage and cleaning of the tire side walls.
Many of these tire cleaning spray systems are actuated in response to one of the vehicle tires passing over a treadleplate or lever located in the path of the moving vehicle. Examples of such constructions are shown in U.S. Pat. Nos. 2,837,759, 3,604,433, 3,679,134 and 3,915,179. Generally, the spray is applied during the time period required for the vehicle to pass between the initial actuating treadle lever and a second or deactivating treadle lever. In other installations, the spray nozzle is actuated the amount of time that a continuous single treadleplate is depressed by the moving tire. Another type of tire washing equipment which is actuated by a single treadleplate, moves brushes into contact with the passing tire and is shown in U.S. Pat. No. 3,662,417.
These prior and existing tire cleaning apparatus, and especially the actuating treadles therefor, have the serious disadvantage of being dependent entirely upon the speed of the vehicle moving through the carwash for controlling the spray time, or else by a predetermined constant spray cycle or time period, which is started by the passing vehicle. In either case, the spray time is constant and has no relationship to the particular size of the vehicle tire being cleaned.
Today's vehicle range from very small compact and sports car models, generally having a nominal thirteen-inch wheel size, through the intermediate vehicle class range, up to and including the large luxury-type vehicle having the nominal fifteen-inch wheel size. These different size vehicles have different size tires, and correspondingly, different size side wall areas to be cleaned. Therefore, a single predetermined spray time period will not economically and effectively clean all size vehicle tires which pass through a carwash in a random fashion.
Many automatic carwash system operators and equipment manufacturers will set the spray time period to the intermediate size vehicle tire size. With this intermediate setting, excess cleaning solution is used for the smaller cars with the resulting uneconomical operation and waste of cleaning solution. Likewise, an insufficient amount of cleaning solution is used for the larger cars resulting in poor cleaning performance and dissatisfied customers. Other settings will result in similar inefficient and/or uneconomical operation. Even though the amount of excess cleaning solution chemical which is sprayed on the smaller vehicle is relatively small per vehicle, it becomes quite substantial when multiplied by the thousands of vehicles which a usual carwash establishment will clean during a period of a year.
Therefore, the need has existed for an inexpensive apparatus for use in cleaning the side walls of the vehicle tires which accurately regulates the spray time and amount of cleaning solution applied to a passing vehicle tire in direct relationship to the size of the particular tires being cleaned. No known apparatus of which I am aware provides a solution to this problem by a relatively simple and inexpensive treadleplate construction having a stepped outer end which provides a series of contact zones of different lengths which regulate the spray application time in direct relationship to the size of the tire of the particular vehicle being cleaned.